Commercial, Farm and Municipality Composting
What is composting?
Composting is the accelerated biological decomposition of organic matter under managed aerobic conditions resulting in a stabilized product that can be used as a soil additive, fertilizer, growth media or other beneficial use (compost).
Composting is the second most preferred method of materials management in EPA’s Waste Management Hierarchy.
Different types of composting
Aerated Static Pile - Process in which decomposing organic material is placed in piles over an air supply system that can be used to supply oxygen and control temperature for the purpose of producing compost. Piles must be insulated to assure that all parts of the decomposing material reach and maintain temperatures at or above 55°C for a minimum of 3 days.
Turned Windrow - Process in which decomposing organic materials are placed in long piles for the purpose of producing compost. The piles are periodically turned or agitated to assure all parts of the decomposing material reach the desired stability.
In-vessel - Process in which decomposing organic material is enclosed in a drum, silo, bin, tunnel, or other container for the purpose of producing compost; and in which temperature, moisture and air-borne emissions are controlled, vectors are excluded and nuisance and odor generation minimized.
Benefits of Composting
There are a number of benefits to compost that not everyone is aware of. Some examples are listed below:
- Organic waste in landfills generates methane, a potent greenhouse gas. By composting wasted food and other organics, methane emissions are significantly reduced.
- Compost reduces and in some cases eliminates the need for chemical fertilizers.
- Compost promotes higher yields of agricultural crops.
- Compost can help aid reforestation, wetlands restoration, and habitat revitalization efforts by improving contaminated, compacted, and marginal soils.
- Compost can be used to remediate soils contaminated by hazardous waste in a cost effective manner.
- Compost can capture and destroy 99.6 percent of industrial volatile organic chemicals (VOCs) in contaminated air.
- Compost can provide cost savings over conventional soil, water and air pollution remediation technologies, where applicable.
How do I get started?
Permit Determination Process
A composting facility is exempt from permitting if:
- You are composting your own material on your own property or leased property and plan to use it on that property (or for agricultural practices at another agribusiness if you are an agribusiness)
- You are composting 400 cubic yards or less per year of yard trimmings or similar material.
- You are composting 100 cubic yards or less per year of food scraps or similar material using an in-vessel composting method or 50 cubic yards per year or less using other methods (windrows, aerated static piles, etc.).
If your operation falls outside the exempt practices, the operation will be required to obtain a permit. Two different types of composting permits exist. Composting facilities processing over 400 cubic yards per year of yard trimmings or similar material may apply for a permit-by-rule. Composting facilities processing more than 100 cubic yards per year of food scraps or similar material using in-vessel composting methods (or more than 50 cubic yards per year using other methods) must apply for a full composting permit.
Applying for a Permit
Submit form CN-1035 to the Division of Solid Waste Management staff at the appropriate Environmental Field Office. See tn.gov/environment/article/permit-waste-solid-waste-management-permit-by-rule for more information.
The applicant must submit the following items to the Division of Solid Waste Management staff at the appropriate Environmental Field Office. A new facility cannot begin construction without submitting Parts I and II and receiving an effective permit.
- A completed application (form CN-1036) which includes the name, address and phone numbers of the owner(s); proposed activities to be conducted at the facility; a statement regarding whether the facility is subject to local approval (TCA § 68-211-701) and county approval if necessary
- A topographic map showing the facility, property boundaries to 1/2 mile past the boundaries, each waste processing or disposal unit, wells, springs, and other surface water bodies within 1/4 mile of the property boundaries
- A disclosure statement containing information concerning past performance in waste management fields of the applicant, officers, directors and/or partners of the applicant's business
- A hydrogeologic assessment of the potential site
- Facility design plans and operations manual
- Financial assurance demonstrating the financial responsibility for closure and post-closure care
- Other specific requirements for Tier II and III composting facilities
The Department offers grants for organics management for municipalities and non-profit organizations. Information will be linked here when available.
- All composting requires four basic ingredients:
- Browns - This includes materials such as dead leaves, branches, and twigs.
- Greens - This includes materials such as grass clippings, vegetable waste, fruit scraps, and coffee grounds.
- Water – Composting organisms need a moist environment.
- Air – Air circulation in the pile will allow the composting organisms the oxygen they need to live and keep the pile from producing a foul odor.
- Initial Parameters for Composting (preferred ranges)
- Moisture: 50-60%
- Carbon to Nitrogen: 25:1-40-1
- Oxygen: Greater than 10%
- Temperature: 120-150°F (49-60°C)
- pH: 6.5-8.0
- Particle Size: the preferred range depends on feedstocks and use of compost, but a reasonable range is 1/8-2 inches
- Bulk Density: 800-1000 lbs/yd3
- Free Air Space: 50-60%
Compost vs. Mulch
- Mulch IS NOT Compost
|Organic in nature||Organic or inorganic in nature|
|Processed to reduce pathogens||Not processed to reduce pathogens|
|The process often requires a Solid Waste Permit||The process does not require a Solid Waste Permit|
|“Earthy” smell (usually)||“Woodsy” smell (usually)|
|Final C:N ratio should be less than 20:1||No ideal C:N ratio, but usually carbon-rich if organic|
|Applied at 2" or less depth or can be incorporated into soil||Applied at least 2-3" deep and not incorporated into soil|
|Can be used as mulch||May turn into a carbon-rich compost-like product if organic|
Other Relevant Information
Cornell University’s Compost Page - good information for large scale and farm composting (including mortality composting)
Register your site at findacomposter.com